Benny Joseph, Technical and Marketing Director, Cooperation between Snibe & Matrix
Arteriosclerosis is the thickening or hardening and loss of elasticity of the walls of arteries. This process gradually restricts blood flow to the organs and tissues. Atherosclerosis is a specific type of arteriosclerosis, entailing the narrowing of arteries from a buildup of plaque (usually made up of cholesterol, fatty substances, cellular waste products, calcium, and fibrin) inside the arteries. This affects large and medium-sized arteries. Atherosclerotic plaques may be stable or unstable. Stable plaques regress, remain static, or grow slowly over several decades, until they may cause stenosis or occlusion. Unstable plaques are vulnerable to spontaneous erosion, fissure, or rupture causing acute thrombosis, occlusion, and infarction long before they cause hemodynamically significant stenosis. Most clinical events result from unstable plaques, which do not appear severe on angiography.
There are numerous risk factors for atherosclerosis including age, sex, family history, dyslipidemia, diabetes, cigarette smoking, hypertension, oxidative stressors, and angiotensin II. Systemic infection and inflammation also inhibit nitric oxide production and stimulate production of adhesion molecules.
Symptoms and Signs
Atherosclerosis is initially asymptomatic, often for decades. Symptoms and signs develop when lesions impede blood flow. Symptoms of unstable angina or infarction, ischemic stroke, or rest pain in the limbs may develop when unstable plaques rupture and acutely occlude a major artery, with superimposition of thrombosis or embolism. Atherosclerosis may also cause sudden death without preceding stable or unstable angina pectoris.
Use of invasive or non-invasive techniques depends on the presence or absence of symptoms and the organs involved. Usually, the patient history, physical examination, fasting lipid profile, HbA1c, hsCRP, CT angiography, angioscopy, plaque thermography, elastography, optical coherence tomography, and the like are the common diagnostic methods for atherosclerosis. The latest diagnostic tool is the estimation of Lp-PLA2 in blood samples.
What is Lp-PLA2?
Lipoprotein-associated phospholipase A2 (Lp-PLA2), also known as platelet-activating factor acetylhydrolase, is a vascular specific inflammatory enzyme that hydrolyzes phospholipids and is primarily associated with low-density lipoproteins (LDLs). It is predominantly expressed by macrophages, lymphocytes, and foam cells in atherosclerotic plaques. Accumulating evidence has suggested that Lp-PLA2 is a biomarker of coronary artery disease (CAD) and may have a pro-inflammatory role in the progression of atherosclerosis.
Why Lp-PLA2 diagnosis?
Many studies confirm a strong relation between Lp-PLA2 levels and cardiovascular risks among different populations. Some studies show that individuals with normal total cholesterol and LDL cholesterol and elevated Lp-PLA2 were found strongly associated with heart disease and ischemic stroke. Increased Lp-PLA2 concentrations were found with patients having vulnerable atherosclerotic plaques, which helped to distinguish between stable and unstable plaques. Lp-PLA2testing is an excellent complement to angiography because it detects very small plaques, which may not be visible by medical imaging.
Lp-PLA2 diagnostic methods
There are a few methods available to detect LPPLA2 activity/Lp-PLA2 mass like EIA, turbidometry, chemiluminescence immunoassay (CLIA), etc.
Lp-PLA2 diagnosis on Maglumi
The Lp-PLA2 assay on Maglumi is a sandwich CLIA, using serum samples. No sample pre-treatment is required for this assay. The assay utilizes monoclonal Ab-coated magnetic microparticles as solid phase and monoclonal Ab-labelled ABEI for conjugate. The assay time is 45 minutes, and results are automatically generated with master curve (i.e., adjusted with two levels of calibrators, provided in the kit). The results are expressed in ng/mL. Internal QC is also provided in the kit. This assay's sensitivity is 1 ng/mL and linearity is up to 1000 ng/mL.
Since Lp-PLA2 diagnosis on Maglumi-CLIA platform is very easy to perform and is more accurate, it can give better clarity about the status of unstable plaques and very small clots inside the arteries of human body and help in effective management of atherosclerosis.